Osteoarthritis treatment

ABSTRACT

The present invention relates generally to a method for the treatment and/or prophylaxis of osteoarthritis (OA). In accordance with the present invention, an antagonist of GM-CSF can be effective in the treatment of osteoarthritis. An antagonist of GM-CSF includes, but is not limited to, an antibody that is specific for GM-CSF or the GM-CSF receptor. The present invention further provides transgenic animals, such as a GM-CSF knock-out mouse, useful for testing antagonists in certain disease models.

This application claims the benefit of U.S. Provisional Application No.61/139,679, filed Dec. 22, 2008, and U.S. Provisional Application No.61/164,486, filed Mar. 30, 2009, which are both incorporated byreference in their entireties.

FIELD OF THE INVENTION

The present invention relates generally lo a method for the treatmentand/or prophylaxis of osteoarthritis (OA). In accordance with thepresent invention, an antagonist of GM-CSF can be effective in thetreatment of osteoarthritis. An antagonist of GM-CSF includes, but isnot limited to, an antibody that is specific for GM-CSF or the GM-CSFreceptor. The present invention further provides transgenic animals,such as a GM-CSF knock-out mouse, useful for testing antagonists incertain disease models.

BACKGROUND OF THE INVENTION

Osteoarthritis (OA), also known as degenerative arthritis, is a diseasemost prevalent in the old and obese. OA is a disease of the articularjoints, but, unlike rheumatoid arthritis (RA), the disease is notsystemic, usually affecting only one or a few joints. The disease leadsto total destruction of the articular cartilage, sclerosis of theunderlying bones and osteophyte formation, resulting in loss of movementand pain. The ultimate result is often the need for a total jointreplacement.

OA affects about ˜21 million people in the US, comprises 25% of allprimary care physician visits, and accounts for 50% of all NSAID (nonsteroidal anti inflammatory drugs) prescriptions. There is currently notreatment available which slows or halts disease progression; today'sdrugs merely treat the symptoms. The incidence and severity of thedisease increase with age. By the age of 65, 80% of Americans showradiographic evidence of OA though only 60% of them will be symptomatic.65% of all joint disease by the age of 65 are OA. In 2006, there were735,000 OA-related US hospitalizations.

Current OA drugs treat the symptoms of OA rather than the diseaseitself. Commonly used drugs in the treatment of OA include Non-steroidalanti-inflammatory drugs (NSAIDs), such as diacerin, voltaren, mobic andarthrotec (generic names: diclofenac, misoprostol, meloxicam). NSAIDsare mainly oral compounds which act by inhibiting prostaglandinsynthesis in the central nervous system (CNS). Other commonly used drugsinclude non-narcotic analgesics, such as ultram (tramadol), COX-2inhibitors, such as celebrax and arcoxia (celecoxib, etoricoxib),narcotic analgesics, such as duragesic (dextropropoxyphene fentanyl),hyaluraonic acids, such as suparts, hyalgan, orthovisc and synvisc(Hylan G-F20), and corticosteroids, such as prednisolone and methylpredinisolone. Present treatments for OA intend to obviate the need forsurgery through tissue engineering, such as chondrocyte transplantation;however, these treatments are only applicable for the treatment of laststage OA. Other approaches in the treatment of OA that are consideredinclude prolotherapy, in which an irritant, such as dextrose, isinjected into the affected joint, thereby causing an acute inflammatoryreaction, but also strengthening and hopefully healing the tissues,ligaments, tendons, and cartilage. There is, thus, a high unmet medicalneed for the treatment of OA.

Some cytokines are known to be involved in osteoarthritis (Blom et al.,Current Drug Targets (2008) 8:283). A few cytokines, such as IL-1, a‘destructive’ cytokine, and the anabolic growth factor transforminggrowth factor β (TGFβ) are considered as potential drug targets.

Granulocyte macrophage colony-stimulating factor (GM-CSF) is a cytokinethat functions as a white blood cell growth factor. GM-CSF stimulatesstem cells to produce granulocytes (neutrophils, eosinophils, andbasophils) and monocytes. Monocytes exit the circulation and migrateinto tissue, whereupon they mature into macrophages. It is, thus, partof the natural immune/inflammatory cascade, by which activation of asmall number of macrophages can rapidly lead to an increase in theirnumbers, a process crucial for fighting infection. The active form ofGM-CSF is found extracellularly as a homodimer. In particular. GM-CSFhas been identified as an inflammatory mediator in autoimmune disorders,like rheumatoid arthritis (RA), leading to an increased production ofpro-inflammatory cytokines, chemokines and proteases and, thereby,ultimately to articular destruction.

WO 06/0234412 discloses numerous biomarkers for osteoarthritis, whichwere identified by protein microarrays. One of the biomarkers identifiedis GM-CSF, for which a four-fold up-regulation is reported in OA tissue.However, no indication or suggestion is provided that GM-CSF may also bea point for therapeutic intervention, and a mere four-fold up-regulationin OA tissue, as identified with the technology disclosed in WO06/0234412, also does not suggest the same. In a related vein,Devalaraja et al (US20020141994A1) cursorily mention OA among a longlist of potentially suitable indications suitable for treatment withantagonists of colony stimulating factors. The list of indicationsincludes atherosclerosis, sepsis, asthma, autoimmune disease,osteoporosis and rheumatoid arthritis. Besides other colony stimulatingfactors, such as M-CSF and G-CSF, GM-CSF is one of the colonystimulating factors mentioned in Devalaraja et al. Indeed, Devalaraja etal. include no data or other insights as to why antagonizing GM-CSFwould be appropriate to treat a subject suffering from OA.

SUMMARY OF THE INVENTION

The present invention, for the first time, demonstrates that GM-CSF is avalid target for the treatment of OA. This finding is new, and the priorart does not teach, suggest or provide any rational for such a point ofintervention in the treatment of OA. Accordingly, the inventionprovides, e.g., a method for the treatment of osteoarthritis in asubject, said method comprising the step of administering an effectiveamount of a GM-CSF antagonist to said subject.

In another aspect, the present invention contemplates a method for theprophylaxis of osteoarthritis in a subject, said method comprising thestep of administering an effective amount of GM-CSF antagonist to saidsubject.

In another aspect, the present invention is directed to a compositioncomprising a GM-CSF antagonist capable of antagonizing the ability ofGM-CSF from activating, proliferating, inducing growth and/or survivalof cells in a subject suffering from osteoarthritis, or being suspectedof suffering from osteoarthritis, said composition further comprisingone or more pharmaceutically acceptable carriers and/or diluents.

In another aspect, the present invention is directed to a compositioncomprising a GM-CSF antagonist useful in the treatment ofosteoarthritis, said composition further comprising one or morepharmaceutically acceptable carriers and/or diluents.

In particular aspects of the present invention, the GM-CSF antagonist isan antibody specific for GM-CSF.

In alternative aspects of the present invention, the GM-CSF antagonistis an antibody specific for the GM-CSF receptor.

In other aspects, the present invention is directed to the use of aGM-CSF antagonist in the preparation of a medicament in the treatment ofosteoarthritis.

In other aspects, the present invention provides GM-CSF antagonists forthe treatment of osteoarthritis.

Throughout this specification, unless the context requires otherwise,the words “comprise”, “have” and “include” and their respectivevariations such as “comprises”, “comprising”, “has”, “having”,“includes” and “including” will be understood to imply the inclusion ofa stated element or integer or group of elements or integers but not theexclusion of any other element or integer or group of elements orintegers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows quantitative data for joint damage in different regionsassessed by histological scoring. The experimental set-up and thescoring system are described in Example 2. “Lat.” stands for lateral.“Med.” stands for medial. Statistical analysis was performed viaMann-Whitney. The data are statistically significant for Lat. Femur(p=0.02). Lat Tibia (p=0.003), Med, Tibia (p=0.001), and over allregions (Mean; p=0.002).

FIG. 2 shows exemplary histology sections of healthy control knees.Magnification is 100×. No cartilage damage, osteophyte formation,synovitis or deformations can be seen. S=synovial lining, C=cartilagelayer.

FIG. 3 shows exemplary histology sections of the left knees of C57/BL6mice in a model of collagenase-induced OA. Magnification is of theindividual sections is indicated in the Figures. The top row of picturesshows that cartilage damage, osteophyte formation and synovitis areevident. O=osteophyte. S=synovial lining. The bottom row of picturesshows that joint deformation is also present.

FIG. 4 shows exemplary histology sections of the left knees of GM-CSF−/−mice in a model of collagenase-induced OA. Magnification is of theindividual sections is indicated in the Figures. As can be seen, theabnormalities and/or damages are much less severe compared to theC57/BL6 mice (see FIG. 3) and are comparably to the healthy control mice(see FIG. 2). O=osteophyte. S=synovial lining.

FIG. 5 shows the knee joint histology scoring of the therapeutictreatment with a GM-CSF antibody in a mouse model of OA. Lat.=Lateral.Med.=Medial. Results are expressed as mean±SEM. As can be seen micetreated with anti-GM-CSF antibody show less disease.

FIG. 6 shows the result of an experiment assessing the hind limb weightdistribution in an incapacitance meter. Data are significant (unpairedt-test) from day 27 post OA induction onwards, as indicated in thegraph.

DETAILED DESCRIPTION OF THE INVENTION

The present invention demonstrates that GM-CSF is a valid target for thetreatment of OA. In this respect, the invention provides, in one aspect,methods of using a GM-CSF antagonist to bring about a prophylactic ortherapeutic benefit in the field of OA.

The present invention provides therapeutic methods comprising theadministration of a therapeutically effective amount, of a GM-CSFantagonist to a subject in need of such treatment. A “therapeuticallyeffective amount” or “effective amount”, as used herein, refers to theamount of a GM-CSF antagonist necessary to elicit the desired biologicalresponse. In accordance with the subject invention, the therapeuticeffective amount is the amount of a GM-CSF antagonist necessary to treatand/or prevent osteoarthritis.

“GM-CSF antagonists”, as used herein, includes GM-CSF antagonists in itsbroadest sense; any molecule which inhibits the activity or function, ofGM-CSF, or which by any other way exerts a therapeutic effect, on GM-CSFis included. The term GM-CSF antagonists includes, but is not limitedto, antibodies specifically binding to GM-CSF, inhibitory nucleic acidsspecific for GM-CSF or small organic molecules specific for GM-CSF. Alsowithin the meaning of the term GM-CSF antagonist are antibodiesspecifically binding to the GM-CSF receptor, inhibitory nucleic acidsspecific for the GM-CSF receptor or small organic molecules specific forthe GM-CSF receptor.

Inhibitory nucleic acids include, but are not limited to, antisense DNA,triplex-forming oligonucleotides, external guide sequences, siRNA andmicroRNA. Useful inhibitory nucleic acids include those that reduce theexpression of RNA encoding GM-CSF by at least 20, 30, 40, 50, 80, 70,80, 90 or 95 percent compared to controls, inhibitory nucleic acids andmethods of producing them are well known in the art. siRNA designsoftware is available.

Small organic molecules (SMOLs) specific for GM-CSF or the GM-CSFreceptor may be identified via natural product screening or screening ofchemical libraries. Typically the molecular weight of SMOLs is below 500Dalton, more typically from 160 to 480 Daltons. Other typical propertiesof SMOLs are one or more of the following:

-   -   The partition coefficient log P is in the range from −0.4 to        ±5.6    -   The molar refractivity is from 40 to 130    -   The number of atoms is from 20 to 70

For reviews see Ghose et al, J Combin Chem: 1:55-68, 1999 and Lipinskiet al, Adv Drug Del Rev 23:3-25, 1997.

Preferably, a GM-CSF antagonist for use in the present invention is anantibody specific for GM-CSF or specific for the GM-CSF receptor. Suchan antibody may be of any type, such as a murine, a rat, a chimeric, ahumanized or a human antibody. A “human” antibody or functional humanantibody fragment is hereby defined as one that is not chimeric (e.g.,not “humanized”) and not from (either in whole or in part) as non-humanspecies. A human antibody or functional antibody fragment can be derivedfrom a human or can be a synthetic human antibody. A “synthetic humanantibody” is defined herein as an antibody having a sequence derived, inwhole or in part, in silico from synthetic sequences that are based onthe analysis of known human antibody sequences. In silico design of ahuman antibody sequence or fragment thereof can be achieved, forexample, by analyzing a database of human antibody or antibody fragmentsequences and devising a polypeptide sequence utilizing the dataobtained therefrom. Another example of a human antibody or functionalantibody fragment is one that is encoded by a nucleic acid isolated froma library of antibody sequences of human origin (i.e., such librarybeing based on antibodies taken from a human natural source).

A “humanized antibody” or functional humanized antibody fragment isdefined herein as one that is (i) derived from a non-human source (e.g.,a transgenic mouse which bears a heterologous immune system), whichantibody is based on a human germline sequence; or (ii) chimeric,wherein the variable domain is derived from a non-human origin and theconstant domain is derived from a human origin or (iii) CDR-grafted,wherein the CDRs of the variable domain are from a non-human origin,while one or more frameworks of the variable domain are of human originand the constant domain (if any) is of human origin.

The term “chimeric antibody” or functional chimeric antibody fragment isdefined herein as an antibody molecule which has constant antibodyregions derived from, or corresponding to, sequences found in onespecies and variable antibody regions derived from another species.Preferably, the constant antibody regions are derived from, orcorresponding to, sequences found in humans, e.g. in the human germ lineor somatic cells, and the variable antibody regions (e.g. VH, VL, CDR orFR regions) are derived from sequences found in a non-human animal, e.g.a mouse, rat, rabbit or hamster.

As used herein, an antibody “binds specifically to”, “specifically bindsto”, is “specific to/for” or “specifically recognizes” an antigen (here,GM-CSF or, alternatively, the GM-CSF receptor) if such antibody is ableto discriminate between such antigen and one or more referenceantigen(s), since binding specificity is not an absolute, but a relativeproperty. The reference antigen(s) may be one or more closely relatedantigen(s), which are used as reference points, e.g. IL3, IL5, IL-4,IL13 or M-CSF. In its most general form (and when no defined referenceis mentioned), “specific binding” is referring to the ability of theantibody to discriminate between the antigen of interest, and anunrelated antigen, as determined, for example, in accordance with one ofthe following methods. Such methods comprise, but are not limited toWestern blots, ELISA-, RIA-, ECL-, IRMA-tests and peptide scans. Forexample, a standard ELISA assay can be carried out. The scoring may beearned out by standard color development (e.g. secondary antibody withhorseradish peroxide and tetramethyl benzidine with hydrogenperoxide).The reaction in certain wells is scored by the optical density, forexample, at 450 nm. Typical background (=negative reaction) may be 0.1OD, typical positive reaction may be 1 OD. This means the differencepositive/negative can be more than 10-fold. Typically, determination ofbinding specificity is performed by using not a single referenceantigen, but a set of about three to five unrelated antigens, such asmilk powder, BSA, transferrin or the like. Additionally, “specificbinding” may relate to the ability of an antibody to discriminatebetween different parts of its target antigen, e.g. different domains orregions of GM-CSF or the GM-CSF receptor, or between one or more keyamino acid residues or stretches of amino acid residues of GM-CSF or theGM-CSF receptor.

Also, as used herein, an “immunoglobulin” (Ig) hereby is defined as aprotein belonging to the class IgG, IgM, IgE, IgA, or IgD (or anysubclass thereof), and includes all conventionally known antibodies andfunctional fragments thereof. A “functional fragment” of anantibody/immunoglobulin hereby is defined as a fragment of anantibody/immunoglobulin (e.g., a variable region of an IgG) that retainsthe antigen-binding region. An “antigen-binding region” of an antibodytypically is found in one or more hypervariable region(s) of an anybody,i.e., the CDR-1, -2, and/or -3 regions; however, the variable“framework” regions can also play an important role in antigen binding,such as by providing a scaffold for the CDRs. Preferably, the“antigen-binding region” comprises at least amino acid residues 4 to 103of the variable light (VL) chain and 5 to 109 of the variable heavy (VH)chain, more preferably amino acid residues 3 to 107 of VL and 4 to 111of VH. and particularly preferred are the complete VL and VH chains(amino acid positions 1 to 109 of VL and 1 to 113 of VH; numberingaccording to WO 97/08320). A preferred class of immunoglobulins for usein the present invention is IgG. “Functional fragments” of the inventioninclude the domain of a F(ab′)₂ fragment, a Fab fragment, scFv orconstructs comprising single immunoglobulin variable domains or singledomain antibody polypeptides, e.g. single heavy chain variable domainsor single light chain variable domains. The F(ab′)₂ or Fab may beengineered to minimize or completely remove the intermoleculardisulphide interactions that occur between the C_(H1) and C_(L) domains.

An antibody of the invention may be derived from a recombinant antibodylibrary that is based on amino acid sequences that have been designed insilico and encoded by nucleic acids that are synthetically created. Insilica design of an antibody sequence is achieved, for example, byanalyzing a database of human sequences and devising a polypeptidesequence utilizing the data obtained therefrom. Methods for designingand obtaining in silico-created sequences are described, for example, inKnappik et al, J. Mol. Biol. 296:57, 2000; Krebs et al, J. Immunol.Methods, 254:67, 2001; Rothe et al, J. Mol. Biol. 376:1182, 2008 andU.S. Pat. No. 6,300,064 issued to Knappik et al 2000 supra, which herebyare incorporated by reference in their entirety.

Any antibody specific for GM-CSF may be used with the present invention.Exemplary antibodies are disclosed in U.S. Ser. No. 11/914,599, which isincorporated by reference in its entirety. Other exemplary antibodiesinclude antibodies comprising an amino acid sequence of a heavy chainvariable region as depicted in SEQ ID NO:1 or an amino acid sequence ofa light chain variable region as depicted In SEQ ID NO:2. Yet otherexemplary antibodies include antibodies which are derived fromantibodies comprising a heavy chain variable region as depicted In SEQID NO:1 or an amino acid sequence of a light chain variable region asdepicted In SEQ ID NO:2. Yet other exemplary antibodies includeantibodies which have the same specificity and/or bind to the sameepitope as antibodies comprising a heavy chain variable region asdepicted in SEQ ID NO: 1 or an amino acid sequence of a light chainvariable region as depicted in SEQ ID NO:2. Yet other exemplaryantibodies include antibodies which comprise a heavy chain variableregion which is at least 70%, at least 80%, at least 90% or at least 95%homologous to the sequence depicted in SEQ ID NO:1. Yet other exemplaryantibodies include antibodies which comprise a light chain variableregion which is at least 70%, at least 80%, at least 90% or at least 95%homologous to the sequence depicted in SEQ ID NO:2.

SEQ ID NO: 1: Met Glu Leu Ile Met Leu Phe Leu Leu Ser Gly ThrAla Gly Val His Ser Glu Val Gln Leu Gln Gln SerGly Pro Glu Leu Val Lys Pro Gly Ala Ser Val LysIle Ser Cys Lys Ala Ser Gly Tyr Thr Phe Thr AspTyr Ash Ile His Trp Val Lys Gln Ser His Gly LysSer Leu Asp Trp Ile Gly Tyr Ile Ala Pro Tyr SerGly Gly Thr Gly Tyr Asn Gln Glu Phe Lys Asn ArgAla Thr Leu Thr Val Asp Lys Ser Ser Ser Thr AlaTyr Met Glu Leu Arg Ser Leu Thr Ser Asp Asp SerAla Val Tyr Tyr Cys Ala Arg Arg Asp Arg Phe ProTyr Tyr Phe Asp Tyr Trp Gly Gln Gly Thr Thr LeuArg Val Ser Ser Val Ser Gly Ser SEQ ID NO: 2:Met Gly Phe Lys Met Glu Ser Gln Ile Gln Val PheVal Tyr Met Leu Leu Trp Leu Ser Gly Val Asp GlyAsp Ile Val Met Ile Gln Ser Gln Lys Phe Val SerThr Ser Val Gly Asp Arg Val Asn Ile Thr Cys LysAla Ser Gln Asn Val Gly Ser Asn Val Ala Trp LeuGln Gln Lys Pro Gly Gln Ser Pro Lys Thr Leu IleTyr Ser Ala Ser Tyr Arg Ser Gly Arg Val Pro AspArg Phe Thr Gly Ser Gly Ser Gly Thr Asp Phe IleLeu Thr Ile Thr Thr Val Gln Ser Glu Asp Leu AlaGlu Tyr Phe Cys Gln Gln Phe Asn Arg Ser Pro LeuThr Phe Gly Ser Gly Thr Lys Leu Glu Leu Lys ArgAla Asp Ala Ala Pro Thr Val Ser Ile Phe Pro Pro Ser Ser Lys Gly Glu Phe

Alternative exemplary antibodies that can be used in the presentinvention are antibodies comprising an amino acid sequence of a heavychain variable region as depicted in SEQ ID NO:3 or an amino acidsequence of a light chain variable region as depicted in SEQ ID NO:4.Other exemplary antibodies include antibodies which are derived fromantibodies comprising a heavy chain variable region as depicted in SEQID NO:3 or an amino acid sequence of a light chain variable region asdepicted in SEQ ID NO:4. Yet other exemplary antibodies includeantibodies which have the same specificity and/or bind to the sameepitope as antibodies comprising a heavy chain variable region asdepicted in SEQ ID NO:3 or an amino acid sequence of a light chainvariable region as depicted in SEQ ID NO:4. Yet other exemplaryantibodies include antibodies which comprise a heavy chain variableregion which is at least 70%, at least 80%, at least 90% or at least 95%homologous to the sequence depicted in SEQ ID NO:3. Yet other exemplaryantibodies include antibodies which comprise a light chain variableregion which is at least 70%, at least 80%, at least 90% or at least 95%homologous to the sequence depleted in SEQ ID NO:4.

SEQ ID NO. 3: heavy MORQVQLVESGGGLVQPGGSLRLSCAASGFTFSSYWMNWVRQAPGKGLEWVSGIENKYAGGATYYAASVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAR GFGTDFWGQGTLVTVSSSEQ ID NO. 4: light MORDIELTQPPSVSVAPGQTARISCSGDSIGKKYAYWYQQKPGQAPVLVIYKKRPSGIPERFSGSNSGNTATLTISGTQAEDEADYYCSAWGDKGMVFGGGTK LTVLGQ

Alternative exemplary antibodies that can be used in the presentinvention are antibodies comprising a H-CDR3 sequence selected from:

(SEQ ID NO. 5) Ser Gly Leu Ile Phe Asp Tyr Trp Leu Asp,1               5                   10 (SEQ ID NO: 6)Ser Gly Leu Ile Ile Asp Ala Leu Ser Pro,1               5                   10 (SEQ ID NO: 7)Thr Ser Leu Met Ser Ile Tyr Phe Asp Tyr,1               5                   10 (SEQ ID NO: 8)Ser Gly Leu Leu Phe Leu Tyr Phe Asp Tyr,1               5                   10 (SEQ ID NO: 9)Ser Gly Leu Ile Asn Leu Gly Met His Pro,1               5                   10 (SEQ ID NO: 10)Ser Gly Leu Ile Phe Asp Ala Leu Arg Asp,1               5                   10 (SEQ ID NO: 11)Ser Gly Leu Ile Phe Asp Lys Leu Thr Ser,1               5                   10 (SEQ ID NO: 12)Ser Gly Leu Ile Asn Leu His Phe Asp Thr,1               5                   10 (SEQ ID NO: 13)Ser Thr His Phe Ser Ala Tyr Phe Asp Tyr,1               5                   10 (SEQ ID NO: 14)Ser Gly Leu Ile Met Asp Lys Leu Asp Asn,1               5                   10 (SEQ ID NO: 15)Ser Gly Leu Ile Ile Asp Asn Leu Asn Pro,1               5                   10 and (SEQ ID NO: 16)Ser Gly Leu Ile Ala Val Tyr Phe Asp Tyr.1               5                   10

Preferably, the antibodies comprising a H-CDR3 sequence selected fromany one of SEQ ID NOs. 5-16, additionally comprise the following H-CDR1sequence:

(SEQ ID NO: 17) Asp Tyr Leu Leu His, 1               5and/or the following H-CDR2 sequence:

(SEQ ID NO: 18) Trp Leu Asn Pro Tyr Ser Gly Asp Thr Asn Tyr Ala1               5                   10 Gln Lys Phe Gln Gly,         15and/or the following L-CDR1 sequence:

(SEQ ID NO: 19) Arg Ala Ser Gln Asn Ile Arg Asn Ile Leu Asn,1               5                   10and/or the following L-CDR2 sequence:

(SEQ ID NO: 20) Ala Ala Ser Asn Leu Gln Ser. 1               5and/or the following L-CDR3 sequence:

(SEQ ID NO: 21) Gln Gln Ser Tyr Ser Met Pro Arg Thr. 1               5

Alternative exemplary antibodies that can be used in the presentinvention are antibodies comprising the following L-CDR1 sequence:

(SEQ ID NO: 22) Arg Ala Ser His Arg Val Ser Ser Asn Tyr Leu Ala,1                5                  10and/or the following L-CDR2 sequence:

(SEQ ID NO: 23) Gly Ala Ser Asn Arg Ala Thr, 1                5and/or the following L-CDR3 sequence:

(SEQ ID NO: 24) Gln Gln Tyr Ala Ser Ser Pro Val Thr, 1                5and/or the following H-CDR1 sequence:

(SEQ ID NO: 25) Gly Tyr Ile Phe Pro Thr Phe Ala Leu His,1                5                   10and/or the following H-CDR2 sequence:

(SEQ ID NO: 26) Ser Ile Asn Thr Ala Ser Gly Lys Thr Lys Phe Ser1                5                   10 Thr Lys Phe Gln,         15and/or the following H-CDR3 sequence:

(SEQ ID NO: 27) Asp Arg Phe Gln Asn Ile Met Ala Thr Ile Leu Asp1               5                   10 Val.

Preferably said antibody comprise all the CRDs of SEQ ID NOs. 22-27.

The GM-CSF receptor is a member of the haematopoietic receptorsuperfamily. It is heterodimeric, consisting of an alpha and a betasubunit. The alpha subunit is highly specific for GM-CSF whereas thebeta subunit is shared with other cytokine receptors, including IL3 andIL5. This is reflected in a broader tissue distribution of the betareceptor subunit. The alpha subunit, GM-CSFR α, is primarily expressedon myeloid cells and non-haematopoetic cells, such as neutrophils,macrophages, eosinophils, dendritic cells, endothelial cells andrespiratory epithelial cells. Full length GM-CSFR α is a 400 amino acidtype I membrane glycoprotein that belongs to the type I cytokinereceptor family, and consists of a 22 amino acid signal peptide(positions 1-22), a 298 amino acid extracellular domain (positions23-320), a transmembrane domain from positions 321-345 and a short 55amino acid intra-cellular domain. The signal peptide is cleaved toprovide the mature form of GM-CSFR α as a 378 amino acid protein. cDNAclones of the human and murine GM-CSFR α are available and, at theprotein level, the receptor subunits have 36% identity. GM-CSF is ableto bind with relatively low affinity to the α subunit alone (Kd 1-5 nM)but not at all to the β subunit alone. However, the presence of both αand β subunits results in a high affinity ligand-receptor complex (Kd

100 pM). GM-CSF signalling occurs through its initial binding to theGM-CSFR α chain and then cross-linking with a larger subunit the commonβ chain to generate the high affinity interaction, which phosphorylatesthe JAK-STAT pathway.

Any antibody specific for GM-CSF receptor may be used with the presentinvention. Exemplary antibodies include antibodies comprising an aminoacid sequence of a H-CDR3 sequence depicted in any one of SEQ IDNo's.:28-46. Other exemplary antibodies include antibodies which arederived from antibodies comprising an amino acid sequence of a H-CDR3sequence depicted in any one of SEQ ID No's.:28-46. Yet other exemplaryantibodies include antibodies which have the same specificity and/orbind to the same epitope as antibodies comprising an amino acid sequenceof a H-CDR3 sequence depicted in any one of SEQ ID No's.:28-46. Yetother exemplary antibodies include antibodies which comprise a H-CDR3sequence which is at least 70%, at least 80%, at least 90% or at least95% homologous to the H-CDR3 sequence depicted in any one of SEQ IDNo's.:28-46.

SEQ ID No: 28: Val Gly Ser Phe Ser Gly Ile Ala Tyr Arg Pro                5                   10 SEQ ID No: 29:Val Gly Ser Phe Ser Gly Pro Ala Lue Arg Pro                5                   10 SEQ ID No: 30:Val Gly Ser Phe Ser Pro Pro Thr Tyr Gly Tyr                5                   10 SEQ ID No: 31:Val Gly Ser Phe Ser Gly Tyr Pro Tyr Arg Pro                5                   10 SEQ ID No: 32:Val Gly Ser Phe Ser Pro Leu Thr Leu Gly Leu                5                   10 SEQ ID No: 33:Val Gly Ser Phe Ser Gly Pro Val Tyr Gly Leu                5                   10 SEQ ID No: 34:Val Gly Ser Phe Ser Pro Pro Ala Tyr Arg Pro                5                   10 SEQ ID No: 35:Val Gly Ser Phe Ser Pro Val Thr Tyr Gly Leu                5                   10 SEQ ID No: 36:Val Gly Ser Phe Ser Gly Leu Ala Tyr Arg Pro                5                   10 SEQ ID No: 37:Val Gly Ser Phe Ser Pro Ile Thr Tyr Gly Leu                5                   10 SEQ ID No: 38:Val Gly Ser Phe Ser Gly Trp Ala Phe Asp Tyr                5                   10 SEQ ID No: 39:Val Gly Ser Phe Ser Gly Trp Ala Phe Asp Tyr                5                   10 SEQ ID No: 40:Leu Gly Ser Val Thr Ala Trp Ala Phe Asp Tyr                5                   10 SEQ ID No: 41:Ala Gly Ser Ile Pro Gly Trp Ala Phe Asp Tyr                5                   10 SEQ ID No: 42:Val Gly Ser Phe Ser Pro Leu Thr Met Gly Leu                5                   10 SEQ ID No: 43:Val Gly Ser Phe Ser Pro Leu Thr Met Gly Leu                5                   10 SEQ ID No: 44:Val Gly Ser Phe Ser Gly Pro Ala Leu His Leu                5                   10 SEQ ID No: 45:Val Gly Ser Val Ser Arg Ile Thr Tyr Gly Phe                5                   10 SEQ ID No: 46:Val Gly Ser Phe Ser Pro Leu Thr Leu Gly Leu                5                   10

In certain aspects, the present invention provides methods for thetreatment of osteoarthritis in a subject, said method comprising thestep of administering a GM-CSF antagonist to said subject. “Subject”, asused in this context refers to any mammal, including rodents, such asmouse or rat, and primates, such as cynomolgus monkey (Macacafascicularis), rhesus monkey (Macaca mulatta) or humans (Homo sapiens).Preferably the subject is a primate, most preferably a human.

In certain aspect, the present invention provides a compositioncomprising a GM-CSF antagonist capable of antagonizing the ability ofGM-CSF from activating, proliferating, inducing growth and/or survivalof cells in a subject suffering from osteoarthritis, or being suspectedof suffering from osteoarthritis, said composition further comprisingone or more pharmaceutically acceptable carriers and/or diluents.Anti-GM-CSF antibodies of the present invention may antagonize any ofthe roles of GM-CSF in osteoarthritis.

In another aspect, the present invention provides a method for theprophylaxis of osteoarthritis in a subject, said method comprisingadministering a GM-CSF antagonist to said subject. “Prophylaxis” as usedin this context refers to methods which aim to prevent the onset of adisease or which delay the onset of a disease.

In certain aspects, the present invention provides a compositioncomprising a GM-CSF antagonist useful in the treatment ofosteoarthritis, said composition further comprising one or morepharmaceutically acceptable carriers and/or diluents

In other aspects, the present invention provides the use of a GM-CSFantagonist in the preparation of a medicament in the treatment ofosteoarthritis.

In other aspects, the present invention provides GM-CSF antagonists forthe treatment of osteoarthritis.

The compositions of the present invention are preferably pharmaceuticalcompositions comprising a GM-CSF antagonist and a pharmaceuticallyacceptable carrier, diluent or excipient, for the treatment ofosteoarthritis. Such carriers, diluents and excipients are well known inthe art, and the skilled artisan will find a formulation and a route ofadministration best suited to treat a subject with the GM-CSFantagonists of the present invention.

In another aspect the present invention provides a geneticallyengineered mammal having a GM-CSF −/− genotype. In particular aspectssaid mammal is a mouse. The terms “knock-out” mouse (or mammal), a mouse(or mammal) “disrupted in” a certain gene, and a mouse (or mammal) witha “−/− genotype” are used interchangeably in the present invention andare art recognized. Respective animals are deficient in a respectivegene, here GM-CSF, on both alleles of the chromosome.

EXAMPLE 1 Generation of a GM-CSF−/− Mouse

The generation of GM-CSF−/− mice is described in Stanley et al (1994).Proc. Natl. Acad. Sci. USA 91:5592. Briefly, chimeric mice weregenerated by microinjection of 129/OLA-derived ES cells (H-2b) with adisrupted GM-CSF gene into C57BL/6 (H-2b) host blastocysts. Germlinetransmitters of the mutated GM-CSF allele were crossed with C57BL/6 micefor 11 generations, giving GM-CSF+/− mice that were interbred to yieldthe GM-CSF−/−, GM-CSF+/−, and GM-CSF+/+ mice used for the experiments.GM-CSF genotype status was determined by PCR analysis of tail DNA.Animals were fed standard rodent chow and water ad libitum and werehoused with same sex littermates in sawdust-lined cages. Mice of bothsexes were consigned to experiments at 8 to 15 wk of age

EXAMPLE 2 Validation of GM-CSF as a Target for Osteoarthritis

GM-CSF−/− mice were compared to C57/BL6 mice (see e.g. Mills et al, JImmunol 164:6166-6173, 2000) in an experimental model of osteoarthritis.

Method: Mice (n=10 per group) received an intra-articular injection ofcollagenase in the left knee on day −2 and day 0 (Blom et al, ArthritisRheum 56:147-157, 2007). At day 42 the mice were killed, the knee jointscollected, fixed, de-calcified, embedded in paraffin and cut at 7 μmwith a microtome. Slides were then stained with Safranin-O/Fast Greenand Haematoxylin and Eosin to demonstrate joint pathology. Pathologyinvestigated includes: cartilage damage, synovitis, osteophyte formationand joint deformation.

The scoring system used for cartilage pathology was as follows:

Grade

-   -   0 Normal    -   1 Irregular but intact    -   1.5 Irregular with rough surface    -   2 Superficial fibrillation    -   2.5 Superficial fibrillation with reduced cells in cartilage        layer    -   3 Vertical fissures    -   3.5 Branching and/or horizontal fissures, tidemark ruptures    -   4 Cartilage loss not extending to the tide mark    -   4.5 Cartilage loss extending to the tide mark    -   5 Cartilage loss beyond the tide mark but not extending to the        bone    -   5.5 Cartilage loss extending to the bone    -   6 Bone loss/remodeling/deformation

Stage

-   -   1 <10% area damaged    -   2 10-25% area damaged    -   3 25-50% area damaged    -   4 50-75% area damaged

The grade was multiplied by the stage to give the score.

This scoring system is based on a recognized method to assess OAhistopathology in clinical and experimental OA. See Pritzker et al,Osteoarthritis Cartilage 14:13-29, 2006. Grade is defined as OA depthprogression into cartilage. Stage is defined as the horizontal extent ofcartilage involvement, i.e. how much of the cartilage is affected. Gradeis multiplied by the stage to give the score to give an overall score,so as to represent a combined assessment of OA severity and extent. Upto six sections are scored per mouse.

Results: Inspection of these joints showed that the GM-CSF−/− mice showless knee joint pathology than the control mice, indicating the role ofGM-CSF in normal osteoarthritis pathology and progression. Pathologyobserved in the C57/Bl6 mice includes severe damage to the cartilagelayer, osteophyte formation, joint deformation and synovitis. TheGM-CSF−/− mice showed no osteophyte formation or joint deformation andmuch less cartilage damage and synovitis.

Quantitative data on-joint damage in different regions are shown inFIG. 1. Representative histology is shown in FIGS. 2 (healthy controlknees), 3 (C57/BL6 left knees) and 4 (GM-CSF−/− left knees). GM-CSFgene-deficient mice developed less collagenase-induced OA pathology,compared to C57BL/6 mice.

In summary, GM-CSF−/− mice showed strongly decreased knee jointpathology compared to C57/BL6 mice in an experimental model ofosteoarthritis and validated GM-CSF as a drug target for therapeuticintervention for osteoarthritis.

EXAMPLE 3 Therapeutic Effectiveness of GM-CSF Antagonists in theTreatment of OA

In this experiment we used a monoclonal antibody specific for GM-CSF todemonstrate that a GM-CSF antagonist can be effective to treatosteoarthritis.

Collagen-Induced OA Mouse Model

C57BL/6 mice were given 1 unit of collagenase type VII intra-articularlyinto the right knee on days 0 and 2 to induce joint instability (seeBlom et al. (2004) Osteoarthritis Cartilage. 12; 627-35).

Anti-GM-CSF Antibody Treatment

20 mice were randomly divided into 2 groups (10 mice/group).

-   -   Group 1 (n=10): anti-GM-CSF antibody (22E9)    -   Group 2 (n=10): IgG2a isotype control antibody.

Mice were treated intraperitoneally, three times per week for 6 weekswith 250 μg/mouse/treatment anti-GM-CSF antibody (22E9) or IgG2aisoptype control antibody. Treatment started 4 days before the inductionof OA (prophylactic), i.e. mice were treated on day −4, day −2, day 0(the day of the first collagenase injection), then 3 times per weekuntil the end of the experiment at 6 weeks). At weeks 2, 4 and 6, micewere bled. Serum will be checked for antibody content and immunogenicityagainst 22E9. Both, the control antibody and the anti-GM-CSF antibodywere purified to contain less than 10 Endotoxin Units/ml.

The antibody 22E9 was used as an exemplary anti-GM-CSF antibody. 22E9,which is of IgG2a isotype, is a rat anti-mouse GM-CSF-specific antibody.22E9 was purchased from AbD Serotec (Martinsried, Germany; Cat. No.1023501). Alternative suppliers exist, e.g. eBioscience (San Diego,Calif., USA, Cat. No. 14-7331).

Histology

6-weeks post final injections, histology was performed on the mice kneejoints. The knee joints were collected, fixed, de-calcified, embedded inparaffin and cut at 7 μm with a microtome. Slides were stained withSafranin-O/Fast Green and Haematoxylin and Eosin to demonstrate jointpathology. Pathology investigated included: cartilage damage, synovitis,osteophyte formation and joint deformation.

The same scoring system as in Example 2 was used for cartilagepathology. Grade was multiplied by the stage to give the score.

The following scoring system was used for synovitis (Synovial layerscoring system):

-   -   0 No changes compared to normal joints    -   1 Thickening of the synovial lining and some influx of        inflammatory cells    -   2 Thickening of the synovial lining and intermediate influx of        inflammatory cells    -   3 Profound thickening of the synovial lining and maximal        observed influx of inflammatory cells

Pain Measurements

An indicator of pain used for OA models is differential distribution ofweight measured using an Incapacitance Meter. This instrument measureschanges in weight distribution between the operated and contralateral,unoperated hind limb. Mice were allowed to acclimatize to the equipmenton three occasions prior to the experiment. Weight placed on each hindlimb was measured over a 5 second period. Three separate measurementstaken per mouse for each time point then averaged. Measurements wereperformed 2 times per week throughout the experiment. Results areexpressed as collagenase injected limb/control limb×100.

Results

For all areas analyzed in histology (except the Medial Femur), i.e. theLateral Femur, the Lateral Tibia, and the Medial Tibia, there was aclear trend towards less disease in mice treated with anti-GM-CSFantibody. Results are depicted in FIG. 5.

Assessment of the weight distribution, as a measure of pain associatedwith the arthritis, showed a significant shift in weight away from thearthritic knee from day 27 onwards in the anti-GM-CSF mAb-treated groupcompared to the control mAb-treated group. Results are depicted in FIG.6.

Mice treated with a GM-CSF antagonist showed less disease as compared tomice treated with the control antibody. Mice treated with the GM-CSFantagonist also showed significantly less pain in the latter stages ofdisease compared to mice treated with the control antibody. Mice treatedwith the isotype control antibody showed significant increased signs ofosteoarthritis as compared lo the mice which received theGM-CSF-specific antibody. This demonstrates that GM-CSF antagonists areeffective in the treatment of OA.

EXAMPLE 4 Therapeutic Effectiveness of a GM-CSF Specific AntibodyComprising SEQ ID NOs. 1 or 2

Example 3 is repeated, whereby as GM-CSF antagonist, a GM-CSF specificantibody comprising an amino acid sequence of a heavy chain variableregion as depicted in SEQ ID NO:1 or comprising an amino acid sequenceof a light chain variable region as depicted in SEQ ID NO:2 is used.Another species than mouse may be used, in particular a species to whichthe antibody used in this experiment is cross reactive. Preferably theanimal species used in this experiment is rat.

The animals treated with the isotype control antibody shows significantincreased signs of osteoarthritis as compared to the animals whichreceived a GM-CSF specific antibody comprising an amino acid sequence ofa heavy chain variable region as depicted in SEQ ID NO:1 or comprisingan amino acid sequence of a light chain variable region as depicted inSEQ ID NO:2. This demonstrates the effectiveness of the antibodies inthe treatment of OA.

EXAMPLE 5 Therapeutic Effectiveness of a GM-CSF Specific AntibodyComprising SEQ ID NOs. 3 or 4

Example 3 is repeated. As GM-CSF antagonist, a GM-CSF specific antibodycomprising an amino acid sequence of a heavy chain variable region asdepicted in SEQ ID NO:3 or comprising an amino acid sequence of a lightchain variable region as depicted in SEQ ID NO:4 is used. Anotherspecies than mouse may be used, in particular a species to which theantibody used in this experiment is cross reactive. Preferably theanimal species used in this experiment is rat.

The animals, e.g. rat, treated with the isotype control antibody showsignificant increased signs of osteoarthritis as compared to the animalswhich received a GM-CSF specific antibody comprising an amino acidsequence of a heavy chain variable region as depicted in SEQ ID NO:3 orcomprising an amino acid sequence of a light chain variable region asdepicted in SEQ ID NO:4. This demonstrates the effectiveness of theantibodies in the treatment of OA.

EXAMPLE 6 Therapeutic Effectiveness of a GM-CSF Specific AntibodiesComprising SEQ ID NOs. 5-20

Example 3 is repeated. As GM-CSF antagonist, a GM-CSF specific antibodycomprising a H-CDR3 sequence selected from any one of SEQ ID NOs. 5-16is used. Preferably, said antibodies additionally comprise the H-CDR1sequence of SEQ ID NO:16, and/or the H-CDR2 sequence of SEQ ID NO:17,and/or the L-CDR1 sequence of SEQ ID NO:18, and/or the L-CDR2 sequenceof SEQ ID NO:19), and/or the L-CDR3 sequence of SEQ ID NO:20. Anotherspecies than mouse may be used, in particular a species to which theantibody used in this experiment is cross reactive. Preferably theanimal species used in this experiment is rat.

The animals, e.g. rat, treated with the isotype control antibody showsignificant increased signs of osteoarthritis as compared to the animalswhich received a GM-CSF specific antibody according to the presentexample. This demonstrates the effectiveness of the anybodies in thetreatment of OA.

EXAMPLE 7 Therapeutic Effectiveness of a GM-CSF Specific AntibodiesComprising SEQ ID NOs. 21-26

Example 3 is repeated. As GM-CSF antagonist, a GM-CSF specific antibodycomprising the L-CDR1 sequence of SEQ ID NO-22, and/or the L-CDR2sequence of SEQ ID NO:23, and/or the L-CDR3 sequence of SEQ ID NO:24,and/or the H-CDR1 sequence of SEQ ID NO:25, and/or the H-CDR2 sequenceof SEQ ID NO:26, and/or the H-CDR3 sequence of SEQ ID NO:27 is used.Preferably said antibody comprise all the CRDs of SEQ ID NOs. 22-27.Another species than mouse may be used, in particular a species to whichthe antibody used in this experiment is cross reactive. Preferably theanimal species used in this experiment is rat.

The animals, e.g. rat, treated with the isotype control antibody showsignificant increased signs of osteoarthritis as compared to the animalswhich received a GM-CSF specific antibody according to the presentexample. This demonstrates the effectiveness of the antibodies in thetreatment of OA.

EXAMPLE 8 Therapeutic Effectiveness of Antibodies Specific for theGM-CSF Receptor

Example 3 is repeated with the difference that a monoclonal antibodyspecific for the GM-CSF receptor is used instead of a monoclonalantibody specific for the GM-CSF.

As GM-CSF antagonist, a GM-CSF receptor specific antibody comprising anamino acid sequence of a H-CDR3 sequence depicted in any one of SEQ IDNo's.:27-45 is used. Another species than mouse may be used, inparticular a species to which the antibody used in this experiment iscross reactive. Preferably the animal species used in this experiment israt.

The animals, e.g. rat, treated with the isotype control antibody showsignificant increased signs of osteoarthritis as compared to the animalswhich received a GM-CSF receptor specific antibody according to thepresent example. This demonstrates the effectiveness of the antibodiesin the treatment of OA.

EXAMPLE 9 Clinical Trial

A clinical trial is performed in adult patients suffering fromosteoarthritis of the knee The objective of the randomized,double-blind, placebo-controlled clinical trial is to determine thecomparative differences between the GM-CSF antagonists of the presentinvention and placebo in overall pain relief and quality of life in atotal sample of 30 patients with diagnosed osteoarthritis (OA) of theknee. Another objective is to determine the safety and tolerability ofthe GM-CSF antagonists of the present invention as determined by theadverse events, physical examination and vital signs.

Methods

Thirty patients (about 15 adult males and 15 adult females), aged 40 andover, with a clinical diagnosis of osteoarthritis of the knee(s) andverified knee pain for at least 15 days in the month prior to testingare enrolled in the study. Patients receive a therapeutically effectiveamount of GM-CSF antagonists or a placebo (e.g. once every two weeks forabout six months).

The Western Ontario and McMaster Universities Osteoarthritis Index(WOMAC; Bellamy et al, J Rheumatol 15(12):1833-40, 1988) and the SF-36v2Quality of Life instrument scales (Quality Metric Health OutcomesSolutions, Lincoln, R.I.) are used in the study. The WOMAC is adisease-specific, self-administered, health status measure. It probesclinically-important symptoms in the areas of pain, stiffness andphysical function in patients with osteoarthritis of the hip and/orknee. The index consists of 24 questions (5-pain, 2-stiffness and17-physical function) and can be completed in less than 5 minutes. TheWOMAC is a valid, reliable and sensitive instrument for the detection ofclinically important changes in health status following a variety ofinterventions (pharmacologic, nutritional, surgical, physiotherapy,etc.). The WOMAC questionnaire is valid for assessing the effects ofintervention on hip or knee osteoarthritis. The SF-36v2 Quality of Lifeinstrument is a multi-purpose, short-form health survey with 36questions. It yields an 8-scale profile of functional health andwell-being scores as wall as psychometrically-based physical and mentalhealth summary measures and a preference-based health utility index. Itis a generic measure, as opposed to one that targets a specific age,disease, or treatment group. Accordingly, the SF-36v2 has proven usefulin surveys of general and specific populations, comparing the relativeburden of diseases, and in differentiating the health benefits producedby a wide range of different treatments. The SF-36v2 yields informationon the following aspects and subsets of health; Physical Health(comprised of physical functioning, role-physical, bodily pain andgeneral health) and Mental Health (comprised of vitality, socialfunctioning, role-emotional and mental health).

Results

Change in bodily pain: The improvement in SF-36v2 bodily pain isstatistically significant in patients treated with the GM-CSFantagonists of the present invention as compared with placebo. A higherscore is better because it means the patient feels less pain aftertaking the product. There is a statistical significant improvement inthe bodily-pain score in the group that received the GM-CSF antagonistsof the present invention versus the placebo group.

Change in role-physical score: The superior effect of the GM-CSFantagonists of the present invention compared with the placebo isstatistically significant in week 8, week 12, and week 20 in terms ofrole limitations due to physical health (role physical). A higher scoreis better because it means that the patient noticed a physicalimprovement and a reduction in the limitations suffered in activities ofdaily living. There is a statistical significant improvement in therole-physical score in the group that received the GM-CSF antagonists ofthe present invention versus the placebo group.

Change in the total WOMAC score: The total WOMAC score of the grouptreated with the GM-CSF antagonists of the present invention isstatistical significantly better than the total WOMAC score of theplacebo group (a lower score is better).

Change in WOMAC ADL: The improvement in activities of daily living(measured as a WOMAC ADL sub-score) is greater in the group treated withthe GM-CSF antagonists of the present invention than in the placebogroup. There is an statistically significant improvement in the WOMACADL score in the group treated with the GM-CSF antagonists of thepresent invention compared to the placebo group (a lower score isbetter).

Conclusions

The clinical trial shows the efficacy of the GM-CSF antagonists of thepresent invention in improving the quality of life of patients withosteoarthritis of the knee. The results of the clinical trial also showthe product's safety and tolerance, given that no serious adverseeffects were found.

The efficacy of the GM-CSF antagonists of the present invention can alsobe established through studies in other species to which the GM-CSFantagonists of the present invention are cross-reactive (e.g. on horsesin order to evaluate joint movement); and by using in vitro studies todetermine the ability of GM-CSF antagonists of the present invention toinhibit IL-1-induced agrecan degradation, concluding the assay oncondrocyte cultures.

Those skilled in the art will appreciate that the invention describedherein is susceptible to variations and modifications other than thosespecifically described. It is to be understood that the inventionincludes all such variations and modifications. The invention alsoincludes all of the steps, features, compositions and compounds referredto or indicated in this specification, individually or collectively, andany and all combinations of any two or more of said stops or features.

BIBLIOGRAPHY

-   Bellamy et al, J Rheumatol 15(12):1833-40, 1988-   Blom et al, Arthritis Rheum 56:147-157, 2007-   Ghose et al, J Combin Chem: 1:55-68, 1999-   Knappik et al, J. Mol. Biol. 296:57, 2000-   Krebs et al, Immunol. Methods. 254:67, 2001-   Lipinski et al, Adv Drug Del Rev 23:3-25, 1997-   Mills et al, J Immunol 164:6166-6173, 2000-   Pritzker et al, Osteoarthritis Cartilage 14:13-29, 2006-   Rothe et al, J. Mol. Biol. 376:1182, 2008

1-5. (canceled)
 6. A method for the treatment of osteoarthritis in ahuman subject, comprising the step of administering to the subject aneffective amount of an antibody specific for the GM-CSF receptor.
 7. Themethod of claim 6, wherein the antibody comprises an amino acid sequenceat least 90% homologous to an amino acid sequence selected from thegroup consisting of the H-CDR3 sequences of SEQ ID NOs: 28-46.
 8. Themethod of claim 6, wherein the antibody comprises an amino acid sequenceat least 95% homologous to an amino acid sequence selected from thegroup consisting of the H-CDR3 sequences of SEQ ID NOs: 28-46.
 9. Themethod of claim 6, wherein the antibody comprises an amino acid sequenceselected from the group consisting of the H-CDR3 sequences of SEQ IDNOs: 28-46.
 10. The method of claim 6, wherein the antibody comprises anH-CDR3 amino acid sequence of SEQ ID NO:
 32. 11. The method of claim 6,wherein the antibody is a chimeric, humanised or human antibody.
 12. Themethod of claim 11, wherein the antibody is a humanised antibody. 13.The method of claim 6, wherein the antibody further comprises one ormore pharmaceutically acceptable carriers or diluents.